I’d recommend doing this on a throwaway branch as follows. If your commits are in the “newlines” branch and you have switched back to your “master” branch already, this should do the trick:
[adam@mbp2600 example (master)]$ git checkout -b tmpsquash
Switched to a new branch "tmpsquash"
[adam@mbp2600 example (tmpsquash)]$ git merge --squash newlines
Updating 4d2de39..b6768b2
Fast forward
Squash commit -- not updating HEAD
test.txt | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
[adam@mbp2600 example (tmpsquash)]$ git commit -a -m "My squashed commits"
[tmpsquash]: created 75b0a89: "My squashed commits"
1 files changed, 2 insertions(+), 0 deletions(-)
[adam@mbp2600 example (tmpsquash)]$ git format-patch master
0001-My-squashed-commits.patch